118 research outputs found
Shock propagation in locally driven granular systems
We study shock propagation in a system of initially stationary hard-spheres
that is driven by a continuous injection of particles at the origin. The
disturbance created by the injection of energy spreads radially outwards
through collision between particles. Using scaling arguments, we determine the
exponent characterizing the power law growth of this disturbance in all
dimensions. The scaling functions describing the various physical quantities
are determined using large scale event driven simulations in two and three
dimensions for both the elastic and the inelastic system. The results are shown
to describe well the data from two different experiments on granular systems
that are similarly driven.Comment: 8 pages, 9 figure
Extrafollicular adenomatoid odontogenic tumor: a case report
Adenomatoid odontogenic tumor (AOT), a benign epithelial odontogenic tumor, constitutes around 2-7% of all odontogenic tumors that are biopsied. This lesion is unique with regard to its clinical, radiographic, and histopathological features making its diagnosis more predictable. This article emphasizes an extrafollicular variant of AOT leading to maxillary anterior jaw swelling along with cortical plate expansion, perforation, and root resorption within a short duration of time pointing towards its aggressive nature
Numbness and bleeding from the ear following inferior alveolar nerve block: report of a case
The inferior alveolar nerve block is a Mandibular nerve block given to anesthetize the mandibular teeth. Due to its proximity to other nerves and muscles and salivary glands it has many complications if the technique in which it is given is wrong. IANB usually presents with mild or minimal complications following it’s administration. The complications that arise are usually reversible when the action of the local anaesthetic wears off. These complications are usually associated with improper technique and anatomical variations, which can be rectified there itself with slight modifications. This is a very rare complication which has been reported where the patient has experienced numbness of the auricle on the side of inferior alveolar injection which lasted for an hour. This is seen due to the accidental anesthetic injection to the auriculotemporal nerve resulting in numbness. To perform successful inferior alveolar nerve blocks it is mandatory to be familiar with anatomical landmarks. Proper technique can reduce the complications
Biorefinery and Hydrogen Fuel Cell Research
In this project we focused on several aspects of technology development that advances the formation of an integrated biorefinery. These focus areas include: [1] establishment of pyrolysis processing systems and characterization of the product oils for fuel applications, including engine testing of a preferred product and its pro forma economic analysis; [2] extraction of sugars through a novel hotwater extaction process, and the development of levoglucosan (a pyrolysis BioOil intermediate); [3] identification and testing of the use of biochar, the coproduct from pyrolysis, for soil applications; [4] developments in methods of atomic layer epitaxy (for efficient development of coatings as in fuel cells); [5] advancement in fermentation of lignocellulosics, [6] development of algal biomass as a potential substrate for the biorefinery, and [7] development of catalysts from coproducts. These advancements are intended to provide a diverse set of product choices within the biorefinery, thus improving the cost effectiveness of the system. Technical effectiveness was demonstrated in the pyrolysis biooil based diesel fuel supplement, sugar extraction from lignocelluose, use of biochar, production of algal biomass in wastewaters, and the development of catalysts. Economic feasibility of algal biomass production systems seems attractive, relative to the other options. However, further optimization in all paths, and testing/demonstration at larger scales are required to fully understand the economic viabilities. The various coproducts provide a clear picture that multiple streams of value can be generated within an integrated biorefinery, and these include fuels and products
A measurement of secondary cosmic microwave background anisotropies with two years of South Pole Telescope observations
We present the first three-frequency South Pole Telescope (SPT) cosmic
microwave background (CMB) power spectra. The band powers presented here cover
angular scales 2000 < ell < 9400 in frequency bands centered at 95, 150, and
220 GHz. At these frequencies and angular scales, a combination of the primary
CMB anisotropy, thermal and kinetic Sunyaev-Zel'dovich (SZ) effects, radio
galaxies, and cosmic infrared background (CIB) contributes to the signal. We
combine Planck and SPT data at 220 GHz to constrain the amplitude and shape of
the CIB power spectrum and find strong evidence for non-linear clustering. We
explore the SZ results using a variety of cosmological models for the CMB and
CIB anisotropies and find them to be robust with one exception: allowing for
spatial correlations between the thermal SZ effect and CIB significantly
degrades the SZ constraints. Neglecting this potential correlation, we find the
thermal SZ power at 150 GHz and ell = 3000 to be 3.65 +/- 0.69 muK^2, and set
an upper limit on the kinetic SZ power to be less than 2.8 muK^2 at 95%
confidence. When a correlation between the thermal SZ and CIB is allowed, we
constrain a linear combination of thermal and kinetic SZ power: D_{3000}^{tSZ}
+ 0.5 D_{3000}^{kSZ} = 4.60 +/- 0.63 muK^2, consistent with earlier
measurements. We use the measured thermal SZ power and an analytic, thermal SZ
model calibrated with simulations to determine sigma8 = 0.807 +/- 0.016.
Modeling uncertainties involving the astrophysics of the intracluster medium
rather than the statistical uncertainty in the measured band powers are the
dominant source of uncertainty on sigma8 . We also place an upper limit on the
kinetic SZ power produced by patchy reionization; a companion paper uses these
limits to constrain the reionization history of the Universe.Comment: 25 pages; 14 figures; Submitted to ApJ (Updated to reflect referee
comments
Microstructural and Microvascular Phenotype of Sarcomere Mutation Carriers and Overt Hypertrophic Cardiomyopathy
BACKGROUND: In hypertrophic cardiomyopathy (HCM), myocyte disarray and microvascular disease (MVD) have been implicated in adverse events, and recent evidence suggests that these may occur early. As novel therapy provides promise for disease modification, detection of phenotype development is an emerging priority. To evaluate their utility as early and disease-specific biomarkers, we measured myocardial microstructure and MVD in 3 HCM groups-overt, either genotype-positive (G+LVH+) or genotype-negative (G-LVH+), and subclinical (G+LVH-) HCM-exploring relationships with electrical changes and genetic substrate. METHODS: This was a multicenter collaboration to study 206 subjects: 101 patients with overt HCM (51 G+LVH+ and 50 G-LVH+), 77 patients with G+LVH-, and 28 matched healthy volunteers. All underwent 12-lead ECG, quantitative perfusion cardiac magnetic resonance imaging (measuring myocardial blood flow, myocardial perfusion reserve, and perfusion defects), and cardiac diffusion tensor imaging measuring fractional anisotropy (lower values expected with more disarray), mean diffusivity (reflecting myocyte packing/interstitial expansion), and second eigenvector angle (measuring sheetlet orientation). RESULTS: Compared with healthy volunteers, patients with overt HCM had evidence of altered microstructure (lower fractional anisotropy, higher mean diffusivity, and higher second eigenvector angle; all P<0.001) and MVD (lower stress myocardial blood flow and myocardial perfusion reserve; both P<0.001). Patients with G-LVH+ were similar to those with G+LVH+ but had elevated second eigenvector angle (P<0.001 after adjustment for left ventricular hypertrophy and fibrosis). In overt disease, perfusion defects were found in all G+ but not all G- patients (100% [51/51] versus 82% [41/50]; P=0.001). Patients with G+LVH- compared with healthy volunteers similarly had altered microstructure, although to a lesser extent (all diffusion tensor imaging parameters; P<0.001), and MVD (reduced stress myocardial blood flow [P=0.015] with perfusion defects in 28% versus 0 healthy volunteers [P=0.002]). Disarray and MVD were independently associated with pathological electrocardiographic abnormalities in both overt and subclinical disease after adjustment for fibrosis and left ventricular hypertrophy (overt: fractional anisotropy: odds ratio for an abnormal ECG, 3.3, P=0.01; stress myocardial blood flow: odds ratio, 2.8, P=0.015; subclinical: fractional anisotropy odds ratio, 4.0, P=0.001; myocardial perfusion reserve odds ratio, 2.2, P=0.049). CONCLUSIONS: Microstructural alteration and MVD occur in overt HCM and are different in G+ and G- patients. Both also occur in the absence of hypertrophy in sarcomeric mutation carriers, in whom changes are associated with electrocardiographic abnormalities. Measurable changes in myocardial microstructure and microvascular function are early-phenotype biomarkers in the emerging era of disease-modifying therapy
Consensus guidelines for the diagnosis and management of pyridoxine-dependent epilepsy due to alpha-aminoadipic semialdehyde dehydrogenase deficiency
Pyridoxine-dependent epilepsy (PDE-ALDH7A1) is an autosomal recessive condition due to a deficiency of α-aminoadipic semialdehyde dehydrogenase, which is a key enzyme in lysine oxidation. PDE-ALDH7A1 is a developmental and epileptic encephalopathy that was historically and empirically treated with pharmacologic doses of pyridoxine. Despite adequate seizure control, most patients with PDE-ALDH7A1 were reported to have developmental delay and intellectual disability. To improve outcome, a lysine-restricted diet and competitive inhibition of lysine transport through the use of pharmacologic doses of arginine have been recommended as an adjunct therapy. These lysine-reduction therapies have resulted in improved biochemical parameters and cognitive development in many but not all patients. The goal of these consensus guidelines is to re-evaluate and update the two previously published recommendations for diagnosis, treatment, and follow-up of patients with PDE-ALDH7A1. Members of the International PDE Consortium initiated evidence and consensus-based process to review previous recommendations, new research findings, and relevant clinical aspects of PDE-ALDH7A1. The guideline development group included pediatric neurologists, biochemical geneticists, clinical geneticists, laboratory scientists, and metabolic dieticians representing 29 institutions from 16 countries. Consensus guidelines for the diagnosis and management of patients with PDE-ALDH7A1 are provided. This article is protected by copyright. All rights reserved
The Impact of Phenotypic and Genotypic G6PD Deficiency on Risk of Plasmodium vivax Infection: A Case-Control Study amongst Afghan Refugees in Pakistan
Analyses of a case-control study among Afghan refugees in Pakistan find that a G6PD (glucose-6-phosphate dehydrogenase) “Mediterranean” type deficiency confers substantial protection against Plasmodium vivax malaria
Long-Lasting Consequences of Neonatal Maternal Separation on Social Behaviors in Ovariectomized Female Mice
Maternal separation (MS) stress is known to induce long-lasting alterations in emotional and anxiety-related behaviors, but effects on social behaviors are not well defined. The present study examined MS effects on female social behaviors in the social investigation (SIT) and social preference (SPT) tests, in addition to non-social behaviors in the open-field (OFT) and light-dark transition (LDT) tests in C57BL/6J mice. All females were tested as ovariectomized to eliminate confounding effects of endogenous estrogen during behavioral testing. Daily MS (3 hr) from postnatal day 1 to 14 did not affect anxiety levels in LDT, but were elevated in OFT with modified behavioral responses to the novel environment. Furthermore, MS altered social investigative behaviors and preference patterns toward unfamiliar stimulus mice in SIT and short- and long-term SPT paradigms. In SIT, MS reduced social investigation duration and increased number of stretched approaches towards both female and male unfamiliar stimulus mice, suggesting increased social anxiety levels in MS females. Similarly, MS heightened levels of social anxiety during short-term SPT but no MS effect on social preference was found. On the other hand, MS females displayed a distinctive preference for female stimuli, unlike control females, when tested for long-term SPT over a prolonged period of 5 days. Evaluation of FosB expression in the paraventricular nucleus, medial and central amygdala following stimulus exposure demonstrated greater number of FosB immunopositive cells in all three brain regions in MS females compared to control females. These results suggest that MS females might differ in neuroendocrine responses toward unfamiliar female and male opponents, which may be associated with modifications in social behaviors found in the present study. Taken together, this study provides new evidence that early life stress modifies female social behaviors by highlighting alterations in behavioral responses to situations involving social as well as non-social novelty
A Measurement of the Damping Tail of the Cosmic Microwave Background Power Spectrum with the South Pole Telescope
We present a measurement of the angular power spectrum of the cosmic
microwave background (CMB) using data from the South Pole Telescope (SPT). The
data consist of 790 square degrees of sky observed at 150 GHz during 2008 and
2009. Here we present the power spectrum over the multipole range 650 < ell <
3000, where it is dominated by primary CMB anisotropy. We combine this power
spectrum with the power spectra from the seven-year Wilkinson Microwave
Anisotropy Probe (WMAP) data release to constrain cosmological models. We find
that the SPT and WMAP data are consistent with each other and, when combined,
are well fit by a spatially flat, LCDM cosmological model. The SPT+WMAP
constraint on the spectral index of scalar fluctuations is ns = 0.9663 +/-
0.0112. We detect, at ~5-sigma significance, the effect of gravitational
lensing on the CMB power spectrum, and find its amplitude to be consistent with
the LCDM cosmological model. We explore a number of extensions beyond the LCDM
model. Each extension is tested independently, although there are degeneracies
between some of the extension parameters. We constrain the tensor-to-scalar
ratio to be r < 0.21 (95% CL) and constrain the running of the scalar spectral
index to be dns/dlnk = -0.024 +/- 0.013. We strongly detect the effects of
primordial helium and neutrinos on the CMB; a model without helium is rejected
at 7.7-sigma, while a model without neutrinos is rejected at 7.5-sigma. The
primordial helium abundance is measured to be Yp = 0.296 +/- 0.030, and the
effective number of relativistic species is measured to be Neff = 3.85 +/-
0.62. The constraints on these models are strengthened when the CMB data are
combined with measurements of the Hubble constant and the baryon acoustic
oscillation feature. Notable improvements include ns = 0.9668 +/- 0.0093, r <
0.17 (95% CL), and Neff = 3.86 +/- 0.42. The SPT+WMAP data show...Comment: 23 pages, 13 figures. Replaced with version accepted by ApJ. Data
products are available at
http://pole.uchicago.edu/public/data/keisler11/index.html or
http://lambda.gsfc.nasa.gov/product/spt/spt_spectra_2011_get.cf
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